U.S., Russia Seek to Revive Syrian Peace Plan

MOSCOW—The U.S. and Russia agreed to renew efforts to bring the warring sides in Syria to the negotiating table, as Secretary of State John Kerry attempted to ease tensions here with one of Syrian President Bashar al-Assad's most influential backers.

But neither Mr. Kerry nor Russian Foreign Minister Sergei Lavrov gave any indication in a joint appearance Tuesday why the new efforts would be more successful than past attempts, all of...